Our main objective is to understand the structure and function of the cytochrome P-450 monoxygenase family of enzymes. These enzymes are widely distributed in nature and constitute important pathways of xenobiotic detoxification and hormone biosynthesis. This project will address the P-450 metabolism of three varieties of terpernoid structures, the bicyclic camphor system, the acyclic linalool system and the monocyclic p-cymene system. The specific aims of this project period are to extend the genetic, physical and biochemical analysis of the P-450cam enzyme to the P-450lin and P-450cym systems. We will examine the organization and regulation of the genes encoding these enzymes, determine the primary structures of these proteins, examine the selectivity of substrates and selective docking of the redox components, and we will attempt to obtain crystals of X-ray diffraction quality in order to provide two new P-450 tertiary structures.